Eye imaging is key to monitoring not only eye-related problems like glaucoma, cataracts, macular degeneration and refractive errors, but also many other chronic and systemic diseases such as diabetes, hypertension and neurological degeneration, all of which also impact vision. In 2010, the World Health Organization estimated that two-hundred and eighty-five million people worldwide exhibit some form of visual impairment. Thirty-nine million people are blind, but for eighty percent of these their sight could have been saved and/or their illness cured. However, ninety percent of these blinded people live in low-income countries. Smart-phone technology is expected to ease this problem if not totally solve it.
Smart-phones are conveniently portable and mobile. Furthermore, today's smart-phones are comparable in processing power to the high-performance personal computer systems of only a half-dozen years ago and to the supercomputers of several decades ago. At the end of 2014, there were some 1.75 billion smart-phone users worldwide, which creates the potential for profound worldwide penetration at the point of care. Smart-phones provide connectivity with the rest of the world in many ways, such as through mobile/cellular data connections, and through Wi-Fi networks. The smart-phone is also versatile, being programmable through “apps.”
A wide variety of smart-phone apps enable the smartphone to image an eye. However, these apps require an adaptor to position and align the eye relative to the smart-phone camera. FIG. 1 shows use of a prior-art adaptor 102 that positions a smartphone 104 to image an eye 106 of a subject 107. Eye 106 is positioned close to, or touching, adaptor 102, which may for example have a rubber eye-piece 103 proximate the eye. A section 108 of adaptor 102 is shaped, or otherwise configured, to constrain smartphone 104 such that a camera 105 of smartphone 104 is aligned with eye-piece 103 to facilitate alignment with eye 106. Adaptor 102 includes lenses, beam-splitters, and illuminators to facilitate capture of the image. To capture an image of the eye, adaptor 102 couples with smartphone 104, which runs an app 110 that is controlled by a user to capture an image of eye 106 when eye-piece 103 is positioned close to, or touching, eye 106. It is not possible to successfully capture an image of the eye using smartphone 104 and app 110 without using adaptor 102.